Effect of Diffusion Behavior on Electrical Features of the Grain Boundary in the Semiconducting Wxides

초록

The electrical features of polycrystalline semiconducting oxides, which were widely used in electrical industries concerning mobile communications, computers, signal processes, power transports, and control systems, are in most uses crucially determined by the structural and chemical chararteristics of the grain boundaries. There have been a few attempts to control the grain boundary structure and chemistry of electronic oxides by synthesizing the ceramics from surface-coated powders. in these techniques, the coating layers of the powders determine the defect chemistry of the grain boundaries. One of the most important advantage of these techniques is the possiblity of distributing additives along the grain boundaries uniformaly. In this technique, it is important to control the distribution of grain boundary materials for the electrical features of semiconducting oxides. It is still indispensable to improve the understanding of the chemical and electrical features of the grain boundaries formed by the coating materials for a better design of the grain boundary-controlled electrical charateristics of the oxides. In this study, the diffusion coeffiecents at grain boundary itn the SrTiO3 Oxides, which were prepared from surface-coated semiconducting powders by hot-pressing techniques, were obtained by using TEM facility; in teh result, the diffusion behavior of the coating materials was predictable. Also, the relation between the electrical features and the distribution of coating materials at the grain boundaries in polycrystalline SrTiO3 oxides was discussed.